1. Field of the Invention
The present invention relates to an in-vivo image acquiring apparatus which is taken into the body of a subject (patient) and acquires in-vivo image information, an in-vivo image receiving apparatus which receives the image information acquired with the in-vivo image acquiring apparatus, an in-vivo image displaying apparatus which displays the image information acquired with the in-vivo image acquiring apparatus, and a noise eliminating method that eliminates fixed pattern noises in the in-vivo image information of the subject.
2. Description of the Related Art
In recent years, in the field of endoscope, a swallow-type capsule endoscope has been proposed. Such capsule endoscope is provided with, in a capsule-shaped case, an imaging unit which acquires in-vivo image information, an illuminating unit which illuminates the imaging regions of which images are taken with the imaging unit, and a transmitting unit which transmits the image information acquired with the imaging unit by radio. The capsule endoscope is swallowed from the mouth of the patient who is the subject and taken into the body of the subject. The capsule endoscope travels inside the body cavity in accordance with its peristaltic motion, takes images inside the body cavity sequentially, and transmits the acquired image information to the outside the body by radio until the endoscope is naturally excreted from the body.
Image sensors including CMOS and CCD are used for taking in-vivo images. Such image sensors generate fixed pattern noises due to fluctuation of output characteristics among each of the pixels and the like. Especially, CMOS image sensor is more likely to generate the fixed pattern noises than CCD does. For a process to eliminate the fixed pattern noises, for a digital camera and the like which are provided with a shutter mechanism, the following process is known. Specifically, as a first step, a black image that includes the fixed pattern noises is acquired by conducting exposure in a state the shutter is closed; then as a second step, the fixed pattern noises are subtracted from the image of the photographic subject which was actually taken. Meanwhile, in the case of the capsule endoscope, as the shutter mechanism is not provided with, the following structure is known, in which the fixed pattern noises are detected by acquiring the black image with the imaging unit in a non-illuminating state by the illuminating unit. (Japanese patent Application Laid-Open No. 2006-20778).